Everyone please help me! Im so worried that my motor may go at any time. I have a 2013 rmz250. after 45hrs on stock piston, i installed a Vertex 13:8.1 HC Piston kit. Thats all i did. No other upgrades. The elevation im at is 5800 ft. Im running vp VPR fuel (50/50) mixture. Also have installed permenently the grey coupler. Iv spoken to wade wilcox at injectioneering and another dude from california who is a rep for Vertex USA. They both said my bike would run great with it and the VPR 50% mix and grey coupler. They are right ...It runs great. BUT!!!! Now i have 17 hrs on motor and its making some SEMI loud clacking sounds. I thought it was valves. So last night i checked Valve Clearance. Intake & Exhaust clearance are spot on. The Timing is spot on. The cam chain has great tension. I checked the compression at WOT is 118 psi. The service limits are 57 - 114psi manuel specs. Bike starts 1st or 2nd kick everytime when cold or hot. Has great throttle response. But when im on the throttle, i hear loud clacking. Like it is the valves or rod. I dont know what else to do without serious;y diving deep.. HEEEEELP! BTW! I have a 2012 rmz4540 and even that monster is quiter than my 250.